Using UIView as a mask in another UIView on Swift

Question

I am developing an xcode application using Swift. My screen has an image of an animal (socket "backImage"), on top of this image I have a view (socket "coverView"), the color is black, which covers the entire screen. So, while you can not see the image of the animal, because in front of it is a "coverView". Then I have another view (the "maskView" socket), which is smaller, and it is above the large "coverView". I want to use this "maskView" as a mask and for this to see "backImage" through it, like a window.

Can anyone figure this out?

Here is my screen, I want to see a female face behind a large gray look through a smaller white look:

Answer 1

alpha , :

let maskView = UIView()
maskView.backgroundColor = UIColor(white: 0, alpha: 0.5) //you can modify this to whatever you need
maskView.frame = CGRect(x: 0, y: 0, width: imageView.frame.width, height: imageView.frame.height)

yourView.addSubview(maskView)

---

EDIT: , , , , .

func setMask(with hole: CGRect, in view: UIView){

    // Create a mutable path and add a rectangle that will be h
    let mutablePath = CGMutablePath()
    mutablePath.addRect(view.bounds)
    mutablePath.addRect(hole)

    // Create a shape layer and cut out the intersection
    let mask = CAShapeLayer()
    mask.path = mutablePath
    mask.fillRule = kCAFillRuleEvenOdd

    // Add the mask to the view
    view.layer.mask = mask

}

, , - , , :

// Create the view (you can also use a view created in the storyboard)
let newView = UIView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height))
newView.backgroundColor = UIColor(white: 0, alpha: 1)

// You can play with these values and find one that fills your need
let rectangularHole = CGRect(x: view.bounds.width*0.3, y: view.bounds.height*0.3, width: view.bounds.width*0.5, height: view.bounds.height*0.5)

// Set the mask in the created view        
setMask(with: rectangularHole, in: newView)

Answer 2

, @Alexandre Lara! !

:

@IBOutlet weak var windowView: UIView!
@IBOutlet weak var bigCoverView: UIView!

func setMask(with hole: CGRect, in view: UIView){

    // Create a mutable path and add a rectangle that will be h
    let mutablePath = CGMutablePath()
    mutablePath.addRect(view.bounds)
    mutablePath.addRect(hole)

    // Create a shape layer and cut out the intersection
    let mask = CAShapeLayer()
    mask.path = mutablePath
    mask.fillRule = kCAFillRuleEvenOdd

    // Add the mask to the view
    view.layer.mask = mask

}

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    let rectangularHole = windowView.frame.integral

    // Set the mask in the created view
    setMask(with: rectangularHole, in: bigCoverView!)

}